Pan should be 8 x 8 x 2 inches. Heat oven to 350 degrees. Mix meat, rice, 1/2 cup water, the onion, salts, garlic powder and pepper. Shape mixture by rounded tablespoonfuls into balls. Place meatballs in ungreased baking dish. Stir together remaining ingredients; pour over meatballs. Cover with aluminum foil; bake 45 minutes. Uncover; bake 15 minutes longer. 4 to 6 servings.